```html
<!DOCTYPE html>
<html lang="zh-CN">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>分布式锁在高并发场景下的应用 - 技术小馆</title>
    <link rel="stylesheet" href="https://cdn.staticfile.org/font-awesome/6.4.0/css/all.min.css">
    <link rel="stylesheet" href="https://cdn.staticfile.org/tailwindcss/2.2.19/tailwind.min.css">
    <link href="https://fonts.googleapis.com/css2?family=Noto+Serif+SC:wght@400;500;600;700&family=Noto+Sans+SC:wght@300;400;500;700&display=swap" rel="stylesheet">
    <script src="https://cdn.jsdelivr.net/npm/mermaid@latest/dist/mermaid.min.js"></script>
    <style>
        body {
            font-family: 'Noto Sans SC', Tahoma, Arial, Roboto, "Droid Sans", "Helvetica Neue", "Droid Sans Fallback", "Heiti SC", "Hiragino Sans GB", Simsun, sans-serif;
            color: #333;
            line-height: 1.6;
        }
        h1, h2, h3, h4 {
            font-family: 'Noto Serif SC', serif;
            font-weight: 600;
        }
        .hero-gradient {
            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
        }
        .card-hover {
            transition: all 0.3s ease;
        }
        .card-hover:hover {
            transform: translateY(-5px);
            box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
        }
        .highlight {
            position: relative;
            z-index: 1;
        }
        .highlight::before {
            content: '';
            position: absolute;
            bottom: 0;
            left: 0;
            width: 100%;
            height: 30%;
            background-color: rgba(118, 75, 162, 0.2);
            z-index: -1;
            transform: skewY(-2deg);
        }
        .mermaid {
            background-color: white;
            border-radius: 0.5rem;
            padding: 1.5rem;
            box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
        }
        .dropcap::first-letter {
            font-size: 4.5rem;
            float: left;
            line-height: 0.8;
            margin-right: 1rem;
            margin-bottom: 0.5rem;
            font-weight: 700;
            color: #764ba2;
        }
    </style>
</head>
<body class="bg-gray-50">
    <!-- Hero Section -->
    <section class="hero-gradient text-white py-20 md:py-32 px-4 md:px-0">
        <div class="container mx-auto max-w-5xl px-4">
            <div class="flex flex-col md:flex-row items-center">
                <div class="md:w-2/3 mb-10 md:mb-0">
                    <h1 class="text-4xl md:text-5xl font-bold mb-6 leading-tight">
                        分布式锁在<span class="highlight">高并发场景</span>下的应用
                    </h1>
                    <p class="text-xl md:text-2xl opacity-90 mb-8">
                        探索Redisson如何通过Lua脚本实现可靠的分布式锁，解决秒杀系统等并发挑战
                    </p>
                    <div class="flex items-center space-x-4">
                        <div class="flex items-center">
                            <i class="fas fa-bolt text-yellow-300 text-xl mr-2"></i>
                            <span>高并发解决方案</span>
                        </div>
                        <div class="flex items-center">
                            <i class="fas fa-lock text-blue-200 text-xl mr-2"></i>
                            <span>分布式锁机制</span>
                        </div>
                    </div>
                </div>
                <div class="md:w-1/3 flex justify-center">
                    <div class="bg-white bg-opacity-10 p-6 rounded-lg border border-white border-opacity-20 backdrop-blur-sm">
                        <i class="fas fa-server text-6xl text-white block mb-4 text-center"></i>
                        <h3 class="text-xl font-semibold mb-2 text-center">关键技术</h3>
                        <ul class="space-y-2">
                            <li class="flex items-center">
                                <i class="fas fa-check-circle text-green-300 mr-2"></i>
                                <span>Redisson框架</span>
                            </li>
                            <li class="flex items-center">
                                <i class="fas fa-check-circle text-green-300 mr-2"></i>
                                <span>Lua脚本实现</span>
                            </li>
                            <li class="flex items-center">
                                <i class="fas fa-check-circle text-green-300 mr-2"></i>
                                <span>秒杀场景优化</span>
                            </li>
                        </ul>
                    </div>
                </div>
            </div>
        </div>
    </section>

    <!-- Main Content -->
    <main class="container mx-auto max-w-5xl px-4 py-16">
        <!-- Intro Section -->
        <section class="mb-20">
            <div class="flex flex-col md:flex-row items-start">
                <div class="md:w-2/3 md:pr-12">
                    <h2 class="text-3xl font-bold mb-6 text-gray-800">高并发环境下的锁机制挑战</h2>
                    <p class="dropcap text-lg text-gray-700 mb-6">
                        在高并发场景下，如电商秒杀系统，锁机制是确保数据一致性和系统稳定的关键。传统单机锁在分布式系统中无法满足需求，因此我们需要分布式锁来协调多个服务实例对共享资源的访问。
                    </p>
                    <p class="text-lg text-gray-700 mb-8">
                        在我们的电商项目商品(item)模块中，特别是秒杀场景下，分布式锁确保了库存扣减、订单创建等关键操作的原子性，防止超卖和重复处理等问题。
                    </p>
                    
                    <div class="bg-blue-50 border-l-4 border-blue-500 p-4 mb-8 rounded-r">
                        <div class="flex">
                            <div class="flex-shrink-0">
                                <i class="fas fa-info-circle text-blue-500 text-xl"></i>
                            </div>
                            <div class="ml-3">
                                <h3 class="text-sm font-medium text-blue-800">为什么需要分布式锁?</h3>
                                <div class="mt-2 text-sm text-blue-700">
                                    <p>
                                        在微服务架构中，服务通常部署在多个节点上。本地锁只能控制单个JVM进程内的线程同步，而分布式锁可以跨JVM、跨服务协调资源访问。
                                    </p>
                                </div>
                            </div>
                        </div>
                    </div>
                </div>
                
                <div class="md:w-1/3 bg-white p-6 rounded-lg shadow-md card-hover">
                    <h3 class="text-xl font-semibold mb-4 text-gray-800 border-b pb-2">秒杀系统关键需求</h3>
                    <ul class="space-y-3">
                        <li class="flex items-start">
                            <span class="bg-purple-100 text-purple-800 rounded-full w-6 h-6 flex items-center justify-center mr-3 flex-shrink-0">
                                <i class="fas fa-check text-xs"></i>
                            </span>
                            <span>高并发处理能力</span>
                        </li>
                        <li class="flex items-start">
                            <span class="bg-purple-100 text-purple-800 rounded-full w-6 h-6 flex items-center justify-center mr-3 flex-shrink-0">
                                <i class="fas fa-check text-xs"></i>
                            </span>
                            <span>数据一致性保证</span>
                        </li>
                        <li class="flex items-start">
                            <span class="bg-purple-100 text-purple-800 rounded-full w-6 h-6 flex items-center justify-center mr-3 flex-shrink-0">
                                <i class="fas fa-check text-xs"></i>
                            </span>
                            <span>避免超卖现象</span>
                        </li>
                        <li class="flex items-start">
                            <span class="bg-purple-100 text-purple-800 rounded-full w-6 h-6 flex items-center justify-center mr-3 flex-shrink-0">
                                <i class="fas fa-check text-xs"></i>
                            </span>
                            <span>系统高可用性</span>
                        </li>
                        <li class="flex items-start">
                            <span class="bg-purple-100 text-purple-800 rounded-full w-6 h-6 flex items-center justify-center mr-3 flex-shrink-0">
                                <i class="fas fa-check text-xs"></i>
                            </span>
                            <span>低延迟响应</span>
                        </li>
                    </ul>
                </div>
            </div>
        </section>

        <!-- Redisson Section -->
        <section class="mb-20">
            <h2 class="text-3xl font-bold mb-8 text-gray-800 text-center">Redisson分布式锁实现原理</h2>
            
            <div class="grid md:grid-cols-3 gap-8 mb-12">
                <div class="bg-white p-6 rounded-lg shadow-md card-hover">
                    <div class="text-purple-600 mb-4">
                        <i class="fas fa-key fa-2x"></i>
                    </div>
                    <h3 class="text-xl font-semibold mb-3 text-gray-800">Lua脚本实现</h3>
                    <p class="text-gray-700">
                        Redisson使用Lua脚本实现加锁和释放锁操作，保证了操作的原子性。在Redis集群中，所有操作要么全部执行，要么全部不执行。
                    </p>
                </div>
                
                <div class="bg-white p-6 rounded-lg shadow-md card-hover">
                    <div class="text-purple-600 mb-4">
                        <i class="fas fa-clock fa-2x"></i>
                    </div>
                    <h3 class="text-xl font-semibold mb-3 text-gray-800">看门狗机制</h3>
                    <p class="text-gray-700">
                        Redisson内置看门狗机制，在锁持有期间会自动续期，防止业务执行时间过长导致锁过期而其他线程获取锁。
                    </p>
                </div>
                
                <div class="bg-white p-6 rounded-lg shadow-md card-hover">
                    <div class="text-purple-600 mb-4">
                        <i class="fas fa-unlock-alt fa-2x"></i>
                    </div>
                    <h3 class="text-xl font-semibold mb-3 text-gray-800">可重入锁</h3>
                    <p class="text-gray-700">
                        支持同一线程多次获取同一把锁，避免死锁，计数器记录重入次数，只有完全释放才会真正解锁。
                    </p>
                </div>
            </div>

            <div class="bg-white rounded-lg shadow-lg overflow-hidden">
                <div class="p-6">
                    <h3 class="text-xl font-semibold mb-4 text-gray-800">Redisson分布式锁代码示例</h3>
                    <div class="bg-gray-900 rounded-lg p-4 mb-4">
                        <pre class="text-green-400 text-sm overflow-x-auto">
                            <code>
// 获取锁
RLock lock = redisson.getLock("seckill:lock:" + itemId);

try {
    // 尝试加锁，最多等待100秒，上锁后10秒自动解锁
    boolean res = lock.tryLock(100, 10, TimeUnit.SECONDS);
    
    if (res) {
        try {
            // 处理业务逻辑
            doSeckillBusiness(itemId);
        } finally {
            lock.unlock();
        }
    }
} catch (InterruptedException e) {
    Thread.currentThread().interrupt();
}
                            </code>
                        </pre>
                    </div>
                    <div class="flex items-center text-sm text-gray-600">
                        <i class="fas fa-info-circle mr-2 text-blue-500"></i>
                        <span>Redisson提供了多种锁类型，如可重入锁(Reentrant Lock)、公平锁(Fair Lock)、联锁(MultiLock)等</span>
                    </div>
                </div>
            </div>
        </section>

        <!-- Visualization Section -->
        <section class="mb-20">
            <h2 class="text-3xl font-bold mb-8 text-gray-800 text-center">分布式锁工作流程</h2>
            
            <div class="mermaid mb-8">
                sequenceDiagram
                    participant Client1
                    participant Redis
                    participant Client2
                    
                    Client1->>Redis: 获取锁(lockKey, clientId, leaseTime)
                    Redis-->>Client1: 返回成功(获取锁)
                    
                    Client2->>Redis: 尝试获取相同锁
                    Redis-->>Client2: 返回失败(锁已被占用)
                    
                    Client1->>Redis: 执行业务操作
                    Client1->>Redis: 释放锁(lockKey, clientId)
                    Redis-->>Client1: 确认释放
                    
                    Client2->>Redis: 再次尝试获取锁
                    Redis-->>Client2: 返回成功(获取锁)
            </div>
            
            <div class="grid md:grid-cols-2 gap-8">
                <div class="bg-white p-6 rounded-lg shadow-md">
                    <h3 class="text-xl font-semibold mb-4 text-gray-800">性能优化技巧</h3>
                    <ul class="space-y-3 text-gray-700">
                        <li class="flex items-start">
                            <span class="bg-blue-100 text-blue-800 rounded-full w-6 h-6 flex items-center justify-center mr-3 flex-shrink-0">
                                <i class="fas fa-bolt text-xs"></i>
                            </span>
                            <span>根据业务合理设置锁超时时间，避免过长或过短</span>
                        </li>
                        <li class="flex items-start">
                            <span class="bg-blue-100 text-blue-800 rounded-full w-6 h-6 flex items-center justify-center mr-3 flex-shrink-0">
                                <i class="fas fa-bolt text-xs"></i>
                            </span>
                            <span>对热点数据采用分段锁，减少锁竞争</span>
                        </li>
                        <li class="flex items-start">
                            <span class="bg-blue-100 text-blue-800 rounded-full w-6 h-6 flex items-center justify-center mr-3 flex-shrink-0">
                                <i class="fas fa-bolt text-xs"></i>
                            </span>
                            <span>使用tryLock而非lock，避免线程长时间阻塞</span>
                        </li>
                        <li class="flex items-start">
                            <span class="bg-blue-100 text-blue-800 rounded-full w-6 h-6 flex items-center justify-center mr-3 flex-shrink-0">
                                <i class="fas fa-bolt text-xs"></i>
                            </span>
                            <span>考虑锁的粒度，避免过大锁范围影响并发</span>
                        </li>
                    </ul>
                </div>
                
                <div class="bg-white p-6 rounded-lg shadow-md">
                    <h3 class="text-xl font-semibold mb-4 text-gray-800">常见问题解决方案</h3>
                    <div class="space-y-4">
                        <div>
                            <h4 class="font-medium text-gray-800 mb-1">锁释放问题</h4>
                            <p class="text-sm text-gray-600">确保在finally块中释放锁，防止异常导致锁无法释放</p>
                        </div>
                        <div>
                            <h4 class="font-medium text-gray-800 mb-1">锁续期问题</h4>
                            <p class="text-sm text-gray-600">对于长任务，启用看门狗自动续期或手动续期</p>
                        </div>
                        <div>
                            <h4 class="font-medium text-gray-800 mb-1">锁竞争激烈</h4>
                            <p class="text-sm text-gray-600">考虑使用Redisson的公平锁或减少锁粒度</p>
                        </div>
                        <div>
                            <h4 class="font-medium text-gray-800 mb-1">Redis主从切换</h4>
                            <p class="text-sm text-gray-600">考虑使用RedLock算法(谨慎评估)</p>
                        </div>
                    </div>
                </div>
            </div>
        </section>

        <!-- Best Practices -->
        <section class="bg-purple-50 rounded-xl p-8 mb-20">
            <h2 class="text-3xl font-bold mb-8 text-gray-800 text-center">秒杀系统最佳实践</h2>
            
            <div class="grid md:grid-cols-2 gap-8">
                <div>
                    <h3 class="text-xl font-semibold mb-4 text-gray-800">多层次防护策略</h3>
                    <div class="space-y-4">
                        <div class="flex items-start">
                            <div class="bg-purple-100 text-purple-800 rounded-lg p-3 mr-4 flex-shrink-0">
                                <i class="fas fa-shield-alt text-lg"></i>
                            </div>
                            <div>
                                <h4 class="font-medium text-gray-800 mb-1">前端限流</h4>
                                <p class="text-gray-600">按钮防抖、验证码、活动开始前按钮禁用</p>
                            </div>
                        </div>
                        
                        <div class="flex items-start">
                            <div class="bg-purple-100 text-purple-800 rounded-lg p-3 mr-4 flex-shrink-0">
                                <i class="fas fa-filter text-lg"></i>
                            </div>
                            <div>
                                <h4 class="font-medium text-gray-800 mb-1">网关层过滤</h4>
                                <p class="text-gray-600">IP限流、用户限流、恶意请求拦截</p>
                            </div>
                        </div>
                        
                        <div class="flex items-start">
                            <div class="bg-purple-100 text-purple-800 rounded-lg p-3 mr-4 flex-shrink-0">
                                <i class="fas fa-database text-lg"></i>
                            </div>
                            <div>
                                <h4 class="font-medium text-gray-800 mb-1">数据库优化</h4>
                                <p class="text-gray-600">库存预热、异步扣减、乐观锁</p>
                            </div>
                        </div>
                    </div>
                </div>
                
                <div>
                    <h3 class="text-xl font-semibold mb-4 text-gray-800">架构设计要点</h3>
                    <div class="space-y-4">
                        <div class="flex items-start">
                            <div class="bg-purple-100 text-purple-800 rounded-lg p-3 mr-4 flex-shrink-0">
                                <i class="fas fa-layer-group text-lg"></i>
                            </div>
                            <div>
                                <h4 class="font-medium text-gray-800 mb-1">分层设计</h4>
                                <p class="text-gray-600">将系统分为接入层、逻辑层、数据层，各司其职</p>
                            </div>
                        </div>
                        
                        <div class="flex items-start">
                            <div class="bg-purple-100 text-purple-800 rounded-lg p-3 mr-4 flex-shrink-0">
                                <i class="fas fa-rocket text-lg"></i>
                            </div>
                            <div>
                                <h4 class="font-medium text-gray-800 mb-1">缓存设计</h4>
                                <p class="text-gray-600">多级缓存，热点数据提前加载</p>
                            </div>
                        </div>
                        
                        <div class="flex items-start">
                            <div class="bg-purple-100 text-purple-800 rounded-lg p-3 mr-4 flex-shrink-0">
                                <i class="fas fa-exchange-alt text-lg"></i>
                            </div>
                            <div>
                                <h4 class="font-medium text-gray-800 mb-1">异步处理</h4>
                                <p class="text-gray-600">消息队列解耦，非核心流程异步化</p>
                            </div>
                        </div>
                    </div>
                </div>
            </div>
        </section>
    </main>

    <!-- Footer -->
    <footer class="bg-gray-900 text-gray-300 py-10">
        <div class="container mx-auto max-w-5xl px-4">
            <div class="flex flex-col md:flex-row justify-between items-center">
                <div class="mb-6 md:mb-0">
                    <h3 class="text-xl font-semibold text-white mb-2">技术小馆</h3>
                    <p class="text-gray-400">探索技术之美，品味架构之道</p>
                </div>
                <div>
                    <a href="http://www.yuque.com/jtostring" class="text-purple-300 hover:text-white transition-colors duration-300 flex items-center">
                        <i class="fas fa-external-link-alt mr-2"></i>
                        <span>访问技术小馆语雀</span>
                    </a>
                </div>
            </div>
            <div class="border-t border-gray-800 mt-8 pt-8 text-center text-sm text-gray-500">
                &copy; 2023 技术小馆. 保留所有权利.
            </div>
        </div>
    </footer>

    <script>
        mermaid.initialize({
            startOnLoad: true,
            theme: 'default',
            flowchart: {
                useMaxWidth: false,
                htmlLabels: true,
                curve: 'basis'
            }
        });
        
        // 平滑滚动
        document.querySelectorAll('a[href^="#"]').forEach(anchor => {
            anchor.addEventListener('click', function (e) {
                e.preventDefault();
                document.querySelector(this.getAttribute('href')).scrollIntoView({
                    behavior: 'smooth'
                });
            });
        });
    </script>
</body>
</html>
```